HEALTH EFFECTS

OF CEREAL FIBRE

Cereal fibre consumption & potential impact

on human health

Cereal fibre

WEIGHT

MANAGE-

MENT

Obesity Cardiovascular

diseases Diabetes Cancers

Healthy lifestyle

CHOLES-

TEROL

REDUCTION

GLYCAEMIC

CONTROL

BOWEL

FUNCTION

GUT

BRAIN/LIVER

AXIS AND

IMMUNOSTIM

ULATION

LIFE EXPECTANCY

CODEX - FIBRE DEFINITION (2008/09)

Dietary fibre1 means carbohydrate polymers with 10 or more monomeric units2,

which are not hydrolysed by the endogenous enzymes in the small intestine of

humans and belong to the following categories:

• Edible carbohydrate polymers naturally occurring in the food as consumed

AND

• Carbohydrate polymers, which have been obtained from food raw material by

physical, enzymatic or chemical means

• Synthetic carbohydrate polymers

which have been shown to have a physiological effect of benefit to health as

demonstrated by generally accepted scientific evidence to competent authorities.

1) Dietary fibre may include fractions of lignin and/or other compounds when

associated with polysaccharides in the plant cell walls (full text of definition:

see explanation below)

2) Decision on whether to include carbohydrates from 3 to 9 monomeric units

should be left to national authorities

Note: oligosaccharides DP 3 – 9 included by EU and many others e.g. Canada, China, Japan

Analysis of dietary fibre

McCleary, 2007

Integrated Procedure: AOAC Method 2009.01

Measuring all fibres included in Codex definition

“Total” Dietary Fibre (AOAC Method 985.29) (AOAC Method 991.43)

Galacto-oligosaccharides (AOAC method 2001.03)

Raffinose/Stachyose

Cellulose Beta-Glucan

Galactomannan Arabinoxylan

RESISTANT STARCH (AOAC METHOD 2002.02)

Pectin Arabinogalactan

POLYDEXTROSE

(AOAC METHOD 2000.11) FIBRESOL 2

(AOAC METHOD 2001.03)

INULIN/FOS (AOAC METHODS 997.08

AND 999.03)

ASSOCIATED COMPONENTS

Cereal fibre in the Codex-classification system

From grain kernels:

• Soluble arabinoxylan from wheat

endosperm

• Resistant maltodextrin from wheat

• Resistant starch from maize

From straw, or husks:

• Cellulosic fibres

Isolated fibre purified, (often) without

co-passengers

Fibre naturally occurring in foods Isolated fibre

Whole grain

Bran

Cereal fibre (with co-passengers)

Starchy

endosperm

Germ

Codex definition of fibre Synthesized fibre

Other classification systems

-

-----------------------------------------------------------------------------------

Dietary fibre

Soluble dietary fibre (SDF)

Insoluble dietary fibre (IDF)

Dietary fibre

Fermentable

Non-fermentable

AOAC Method 991.43

measures SDF and IDF

separately

Adapted from: Surget, A.; Barron, C., Histologie du grain de blé. Industrie des

Céréales 2005, 145, 3-7.

Hemery, Y.; Rouau, X.; Lullien-Pellerin, V.; Barron, C.; Abecassis, J., Dry processes

to develop wheat fractions and products with enhanced nutritional quality. Journal of

Cereal Science 2007, 46, (3), 327-347

Cereal DF (g/100g)

Wheats 12

Oats 11

Barley 16

Maize 7

Rye 15

Rice 4

Millet 9

Sorghum 6

Teff 8

Pseudo Cereal

Wild rice 6

Amaranth 7

Buckwheat 10

Quinoa 7 Data provided from USDA National Nutrient

Database for Standard Reference. Cereal

grains fiber content (available 2013-04-25).

http://ndb.nal.usda.gov/ndb/search/list

Fibre in cereals and location of bioactive

compounds

Dietary fibre content in different cereal

fractions (g/100g DM)

Fraction Wheat Oats Rye Rice Maize

Whole grain 12 11 15 4 7

Bran 43 15 44 # 21 79

Starchy

endosperm 2.7 6.5 8 2 1.9

Germ 13 - - -

Data provided from USDA National Nutrient

Database for Standard Reference. Cereal grains

fiber content (available 2013-04-25).

http://ndb.nal.usda.gov/ndb/search/list

#Kamal-Eldin et al. (2009) Food Nutr Res.

Free and bound phytochemicals

associated with fibre

Free Bound

Hydrocinnamic acids such

as ferulic, p-comaric and

sinapic acids and their

dimers are present to greater

extent in cereals (mainly

bound) than in fruits and

vegetables. (Neacsu et al.

(2013) Food Chemistry)

Compound Wheat

(µg/100g) Rye (µg/100g)

Tocols 28-80 44-67

Phenolic acids

(90-95% bound) 326-1171 491-1082

Plant sterols 670-960 1098-1420

Alkylresorcinols 241-677 797-1231

Lignans 3.4-23 25-67

Benzoxazinoids 4.8 95

Differences in the contribution of fibre from grain

fractions to Guidelines Daily Amounts (GDA)

GDA (25 g total fibre per day)

0 20 40 60 80 100 120 140 160 180 200

% of GDA

Inta

ke

of

10

0 g

Oat bran

Sifted rye flour

Rye

bran

Sifted oats

Whole grain rye

Wheat

bran

Sifted rye

Refined wheat

Whole grain wheat

Source: National Nutrient Database for Standard Reference (Release 24), ARS, USDA

Overweight – a growing European problem

Percentage of males overweight

(BMI ≥25) 2010

Source: WHO Global Database on Body Mass Index 2010

Obesity – a major risk factor of diabetes, cardiovascular disease and maybe cancer

Source: WHO Global Database on Body Mass Index 2010

Percentage of males obese

(BMI ≥30) 2010

Diabetes – growing national prevalence

> 12% > 10% > 8% > 6% < 6% > 15%

2013 2035

Source: International Diabetes Federation, Diabetes Atlas 6th edition 2013

The main cause of death in the EU is

Cardiovascular disease (CVD)

Death by cause, WOMEN

• Coronary heart disease (CHD) and stroke are the main forms of CVD

• CVD causes 47% of all deaths in Europe and 40% in EU

The main cause of death in the EU is

Cardiovascular disease (CVD)

Death by cause, MEN

• Coronary heart disease (CHD) and stroke are the main forms of CVD

• CVD causes 47% of all deaths in Europe and 40% in EU

Colorectal cancer

Colorectal cancer is the second

most common cause of cancer

death in both men and women!

Source: International Agency for Research on Cancer, World Health Organization

Estimated mortality from cancer of the large bowel in both sexes, 2012

Estimated

age-standardized

incidence rates

per 100.000 of

cancer in the

large bowel

(2012)

Health effects of cereal fibre

Current status on cereal fibre and health effects

EU approved health claims

Official recommendations

by Nutritional Societies

Results from systematic

reviews and meta-

analyses

Type 2 Diabetes (T2D)

Cardiovascular disease

(CVD)

Colorectal cancer (CRC)

Nutrition claims for fibre (including cereal

fibre): EU and other regulations:

Nutritional statements on products in Europe are regulated in

SOURCE OF FIBRE: Foods with at least 3g fibre/ 100g or 1,5 g /100 kcal

HIGH FIBRE Foods with at least 6g fibre/ 100g or 3 g /100 kcal

INCREASED FIBRE Foods being at least a source of fibre and with at least

30% more fibre than a similar product

CODEX recommendations for Source of

and High list as additional option 10 % and

20% of daily reference value per serving.

REGULATION (EC) No 1924/2006

on nutrition and health claims made on foods – Annex 1

EU authorized Health Claims on

Cereal Fibre- Laxation

Material Health claim Conditions of use EFSA opinion

reference

Rye fibre Normal bowel

function

Foods should be high

in that fibre

(i.e. fibre ≥ 6g/ 100g

product) and daily

intake ≥ 10g is

required

2011;9(6):2258

Barley grain

fibre

Increase in

faecal bulk 2011;9(6):2249

Oat grain fibre Increase in

faecal bulk 2011;9(6):2249

Wheat bran

fibre

Increase in

faecal bulk 2010;8(10):1817

Wheat bran

fibre

Accelerated

intestinal

transit

Foods should be high

in that fibre

and daily intake ≥

10g is required

2010;8(10):1817

EFSA Journal 2009; 2010; 2011;

EU authorised Health Claims on Cereal

Fibre and Cholesterol levels

Material Health claim Conditions of

use

EFSA

opinion

reference

β-glucans

(Bg)

Maintenance of normal

cholesterol levels

(Article 13.1 claim)

Daily intake of 3 g

required

Food with ≥ 1 g of Bg

per quantified portion.

2009;7(9):1254

,

2011;9(6):2207

Oat

β-glucan

Oat (respectively barley)

beta-glucan has been

shown to lower/reduce

blood cholesterol. High

cholesterol is a risk factor

in the development of

coronary heart disease

Article 14.(1)(a) claim

(disease reduction claim)

Daily intake of 3 g

required

Foods which provide

at least 1g of oat

(respectively barley)

per portion

Q-2008-681

Barley

β-glucan

Q-2011-00798

and

Q-2011-00799

EU authorised Health Claims on Cereal Fibre

and reduced glucose rise after a meal

Material Health claim Conditions of use

EFSA

Opinion

Reference

Arabinoxylan

produced

from wheat

endosperm

Reduction of

blood glucose

rise after a

meal

Daily intake ≥ 8g AX

rich fibre

2011;9(6):2205

β-glucans

from oats

and barley

Intake ≥ 4g / 30g

digestible carbs

2011;9(6):2207

Resistant

starch (RS)

RS Content ≥ 14% of

total starch

2011;9(4):2024

Evidence level: A (strong evidence)- D (inadequate evidence)

Scientific Statements of Cereal Fibre and Disease

T2D Obesity CVD Hypertension

Cereal Fibre B B/C B D

Mixtures of whole

grains and bran

B B/C B D

Whole grains C C/D C D

Cho et al. Am J Clin Nutr (2103)

The ASN position: Consumption of foods rich in cereal fibre or mixtures of whole

grains and bran is modestly associated with a reduced risk of obesity (B/C), T2D

(B), and CVD (B).

Statement based on current available literature from 1965-2010.

No long-term RCTs (>1y) using cereal fibre was available for disease endpoint.

German Nutrition Society - Cereal Fibre

and Disease

High intake of cereal fibre or whole grain products is associated with a lower

risk of type 2 diabetes mellitus, hypertension and coronary heart disease.

Less strong evidence for overweight/obesity compared to CVD and T2D. More

research is needed.

High intake of cereal fibre is associated with lower risk of developing colorectal

cancer.

German Nutrition Society – Summary of Evidence

T2D CHD Stomach

cancer Colon

cancer Obesity

Total dietary fibre (DF) O ↓↓ ~ ↓ ↓↓

DF from cereal products ↓↓ ↓ ↓ ↓↓ ─

Wholegrain products ↓↓ ↓↓ ─ ─

↓

Legend ─ not assessed O possible evidence, no association

↓ possible evidence, risk reducing ↓↓ probable evidence, risk reducing

~ insufficient evidence

Hauner et al. Ann Nutr Metab. 2012;60 Suppl 1:1-58

Whole grain, dietary fibre, and disease - review

Review and meta-analysis of 45 prospective cohorts and 21 randomized

intervention trials indicates that increased intake of whole grain and fibre may

lower the risk of T2D, CVD, and weight gain.

Highest vs lowest cereal fibre intake was associated with a 16% and 19%

lower risk of developing T2D and CVD, respectively.

Long-term RCTs seem warranted to elucidate mechanisms underlying the

potential beneficial effects for the prevention of chronic diseases.

Ye et al. J Nutr. 2012 Jul;142(7):1304-13.

Dietary Fibre and CVD Dietary fibre intake and risk of cardiovascular disease:

systematic review and meta-analysis

Threapleton et al. (2013) BMJ

Total DF is associated with lower risk of stroke (RR decreased with 17% per 7g/d).

Studies differ considerably.

Separate investigation of fibre from different sources warrented!

Cereal fibre and stroke- more data needed

DF and colorectal cancer- cereal fibre

appears more effective than other fibres

A high intake of dietary fibre, in particular from cereals, is associated with a

reduced risk of colorectal cancer

Similar results from EPIC as shown by Aune et al.

PLoS One. 2012;7(6):e39361. doi:

10.1371/journal.pone.0039361

Dietary fibre and Breast Cancer

Total dietary fibre was associated with lower risk of breast cancer

(relative risk reduction of reduction of 15% per 10g/d, n=16

prospective studies)

Further studies of specific types of fibre should be undertaken

Fibre from different sources and mortality in Europeans

High fibre intake, mainly from cereals and vegetables, may reduce the risk of

death from circulatory, digestive and non-CVD non-cancer inflammatory

diseases

Hazard risk (HRs) and 95% confidence interval (CI) of total death and cause-specific

deaths per 5-g/d increase in fiber intake in men (A) and women (B)

Chuang et al.

(2012), Am J

Clin Nutr.

Dietary fibre showed significant advantage over placebo in stool

frequency (19%, P<0.05)

No difference in stool consistency, treatment success, laxative use

and painful defecation compared to control

(2012), World J Gastroenterol

Cereal fibre and weight management- results from

observational studies and RCTs

Epidemiological studies have shown inverse

associations between cereal fiber intake and BMI,

weight gain and body fat (Mckeown et al. (2009) J Nutr; Koh-Banerjee et al. (2004) Am

J Clin Nutr)

Observational studies:

Randomized controlled trails:

Whole grain consumption does not decrease body

weight compared with control, but small beneficial effect

on body fat may be present (Pol et al. (2013) Am J Clin Nutr.)

Health effects of dietary fibre –

suggested mechanisms

Blood lipids

GI and/or IL

Body weight

Blood pressure

Colonic

fermentation

(SCFA) Insulin sensitivity

Oxidation/

inflammation

Tumour growth

homocysteine

Effect on intermediate endpoint

Effect on hard endpoint

Dietary fibre complex

Fermentable CHO Non-fermentable CHO Phytochemicals

CANCERS TYPE 2 DIABETES CVD

Mortality

Hot research topics on cereal fibre

Cereal fibre and effects on:

Immune system

• Role of prebiotics in inflammatory bowel disease (J Biol Regul Homeost Agents

(2013;27(4):919-33.)

• Immune effects of oligosaccharides (Am J Clin Nutr. 2013;98(2):572-7S)

Mental function

• Effects on memory (episodic, semantic, and workingmemory), language,

attention, executive function, and information processing speed (Nutr Rev.

2014 Mar;72(3):162-79)

”Gut-brain &/or- liver” axis

Influence of the microbial-mammalian metabolic axis with implication for

energy metabolism, appetite and cognitive functions. Effects of cereal

fibre fermentation products such as SCFA on host health Nature 2008 Apr;24:452(7190):1012-6.; Nat Rev Gastroenterol Hepatol 2012 Oct 9 (10):577-89) Curr opin

Microbiol. 2013;16:246-254; Hepatology 2008;sept;48(3):1011-3; Plos Pathog. 2013;9(11): e1003726; Cell 2014 Jan

16;156(1-2):84-96..

Recommended dietary fibre consumption across

the world

Intake/

day

Remarks

EFSA (2010) 25 g 25 g is adequate for normal laxation in adults.

Diets rich in fibre containing foods at DF intakes ≥ 25g

are associated with additional health benefits

WHO (2003) ≥ 25g Total dietary fibre from whole grain cereals, fruit and

vegetables

Germany, Aus-

tria, Switzer-land

(D-A-CH,2008)

≥ 30g At least 30 grams of dietary fibre daily, especially from

whole-grain products

Netherlands

(GR, 2001, 2006)

30-40g 30-40 g dietary fibre via products not enriched with isolated

and purified dietary fibre

Nordic Countries

(NNR 2012)

25-35g

USA (IoM, 2005) 25-38g Total fibre from whole grain cereals, fruit and vegetables for

women and men, respectively

USA

(USDA, 2010)

Consuming enough whole grains helps meet nutrient

needs. Choosing whole grains that are higher in dietary

fibre has additional health benefits

UK (DoH, 1991) 18 g (NSP) 18 g non-starch polysaccharides

Van Der Kamp and Lupton 2013

Examples of foods high in cereal fibre

Concluding remarks

Dietary fibre is defined world-wide

Whole grains, especially from wheat, rye, oats and barley, and

bran products are good sources of dietary fibre (cereal fibre)

High cereal fibre intake is associated with a reduced risk of

obesity, T2D, CVD and colorectal cancer’

Β-glucans (>3g/d) from oats and barley reduce cholesterol and

improves glycaemic response after a meal (>4g per 30g CHO)

Among the dietary fibre sources, cereal fibre show stronger

beneficial associations with non-communicable diseases

Many different mechanisms have been suggested for attributing

protective effects to properties of fibre such as solubility,

viscosity, fermentability and associated bioactive compounds.

THANK YOU FOR YOUR ATTENTION!

For more information please visit www.healthgrain.org

The HEALTHGRAIN EU Integrated Project (2005-2010) - the largest cereal

project ever – has substantially strengthened the scientific basis for a new

generation of cereal products with enhanced health benefits.

The Healthgrain Forum (www.healthgrain.org) has been initiated in 2010 for

continuing HEALTHGRAIN’s research, networking and communication activities.

Currently (status October 2014) 54 member organisations joined, with an even

balance between academia, research organisations, industry and members

focusing on communication on grains and health.

The Healthgrain Forum will evaluate and update this presentation annually. For

questions and suggestions please contact:

jan-willem.vanderkamp@tno.nl

ANNEX

Content

- Fibre analysis – comparison of old and new AOAC Methods

- EU Health Claims on Fibre and Cereal Fibre

Fibre measured with AOAC Methods 985.29 (‘old’) and

2009.01 (‘new’) Data from Brunt and Sanders, Food Chemistry 140 (2013) 574-580

EU Health Claims on fibre and cereal fibre

After adoption of Regulation (EC) 1924/2006:

• Submission of many thousands health claims for evaluation

• In depth evaluation by EFSA of 2245 eligible claims

• Authorisation by EU of 250 health claims

Overview of all 2245 claims: http:// ec.europa.eu/nuhclaims

Examples of non-authorised health claims:

Material Health claims Non authorised, reason

Dietary fibre Various claims, including

- laxation/ bowel function

- Reduction of blood

glucose rise after a meal

- Maintenance of normal

cholesterol levels

insufficiently characterised

Soluble fibre insufficiently characterised

Resistant wheat dextrins Evidence is insufficient